2004 * XV * 3

A. Kureoja, T. Kaart.  
  Piima karbamiidisisaldust mõjutavatest keskkonna- ja geneetilistest faktoritest 131
About environmental and genetic influences on milk urea concentration. If urea is at high level in cow blood, as well in milk, this may cause for it fertility problems. The objectives of this study were to determine the effect of sire, owner, farm, lactation number, sire-owner interaction, owner-lactation number interaction on (MU) concentration, also heritability of (MU) concentration and its genetic and phenotypic correlations with yields of milk, fat, protein, and fat and protein content. This study was based on the data of the Estonian Red (ER) and Estonian Holstein (EHF) cows that started lactating in January, 2002. The data was processed by using SAS program, and the variance components were estimated by REML method. Heritabilities were estimated on the basis of sire model. The statistically significant factors affecting the milk urea concentration appeared to be owner, farm nested to owner, and sire. The results of ER breed were similar to those of EHF breed. The interaction between sire and owner was statistically insignificant. Neither had the lactation-owner interaction nor the lactation number any effect on urea concentration in milk. The heritability of milk urea concentration of the Estonian Red breed cows appeared to be 0.32, and that of the Estonian Holsteins was 0.50. Phenotypic and environmental correlations between milk urea concentration and milk yield traits were in ER and EHF breeds similar, whereas genetic correlations in ER breed were weakly positive and in EHF breed, on the contrary, weakly negative. Thus, selection of EHF toward decrease in milk urea content may lead to some increase in lactation milk yield. The management is an important source of variability and has a crucial role in maintaining optimum MU level. At the same time, the heritabilities are moderate and selection could be an effective approach for altering MU.

Keywords: milk urea concentration, heritability, genetic correlation, cow

O. Kärt, M. Ots, E. Rihma.  
  Piima karbamiidisisalduse ja ratsiooni toitefaktorite vahelistest seostest 137
Relationship between milk urea content and nutritional factors of ration. In order to explain which indices and how precisely can predict milk urea content in diet formulation, a database was formed on the basis of the results of physiological experiments arranged at Eerika experimental farm. All experiments were conducted in a 4×4 Latin square design; cows were fed grass silage ad libitum and concentrate 25, 40, 55 or 75% of metabolisable energy (ME) requirement. Daily amounts of the dry matter (DM) of consumed silage, barley meal and protein feed were 6.8 to 16.8 kg; 1.1 to 10.5 kg and 0 to 2.5 kg, respectively. Daily FCM yield of the cows fluctuated from 13 to 30.4 kg per day and milk urea content from 212 to 459 mg/l. Additionally to generally accepted contents of nutritive factors, the content of metabolisable protein (MP) in the ration and protein balance in the rumen (PBV) were calculated according to the scheme similar to that applied in Finland. Milk urea content correlated positively with crude protein (CP) content (P<0.0001), CP intake (P=0.0003) and PBV (P<0.0001); and negatively with MP intake. Precisest prediction of milk urea content can be done on the basis of CP:ME ratio.

Keywords: ruminant, dairy cow, nitrogen metabolism, milk urea content

E. Reintam, J. Kuht.  
  Muutused odra toitainete tarbimises sõltuvalt liigtihendatud mulla agroökoloogilisest seisundist 146
Changes in barley (Hordeum vulgare L.) nutrients uptake depending on agroecological conditions of overcompacted soil. Soil compaction is one of most harmful soil degradation phenomena. The main objective of this work was to investigate the effect of different machinery use and overridding times on soil properties and barley (Hordeum vulgare L.) and weeds nutrient uptake. Data were collected from Estonian Agricultural University research field (58º23´N, 26º44´E) with different levels of soil compaction (4 levels) on sandy loam soil in 1997, 1998, 2001 and 2002. The results of two different field experiment showed that the most important factors at moment of soil compaction were inflation pressure caused by machinery, times of passage and soil moisture. Compaction with 4.9 Mg tractor did not cause any significant increase of soil bulk density in the first year at soil moisture 11% in either variants and in most soil layers. The second year overridding 1-, 3- and 6-times by 4.9 Mg tractor at 20% soil moisture increased the soil bulk density from 1.49 Mg m-3 in control variant to 1.64 Mg m-3 in most compacted variants. At the same time the compaction with 17.4 Mg tractor caused drastic changes in soil bulk density and penetration resistance in all soil layers already with two times compaction in first year. The total porosity of soil decreased more than 70% compared with uncompacted area. The nutrient uptake by plants was almost the same with given fertilizers (N80, P40, K40) by normal soil bulk density. In dense soil the uptake of nutrients was reduced up to 70%. Soil compaction decreased competiveness of barley and increased share of weeds from 20% up to 53%. More than half from accumulated nutrients on dense soil was in weeds. The reducing of nutrient yield was connected not only with lower shoot yield but also with decreased nutrient content in dry matter. Final effect of soil compaction on plant productivity depends from soil moisture at compaction time and from weather conditions during vegetation period.

Keywords: heavy machinery, compaction, nutrients, barley (Hordeum vulgare L.) weeds

B. Reppo, E. Mikson, V. Vaarak.  
  Soojustamata lauda lüpsikoja sisekliima talvel 155
Indoor climate of uninsulated cowshed’s milking house during wintertime. In last decades in the world building of simply covered uninsulated (cold) cowsheds has been propagated. Animals are kept loosely in sheds on straw bedding (deep litter) or without bedding (resting boxes, cubicles). Popularity of these sheds is caused by smaller building costs. The same situation is normally with milking houses of such cowsheds.

As the indoor climate of an uninsulated shed and milking house is greatly influenced by outside climate, air temperature and relative humidity have been mainly studied; based on which ventilation systems of rooms are suggested. Researches have been made mainly on smaller sheds, but the tendency to build larger sheds has become actual.

The article presents methods and results of indoor climate parameters, observed during wintertime in uninsulated cowsheds milking houses (420, 352 and 730 cows, respectively). Indoor temperature, relative humidity, air velocity and direction, oxygen, carbon dioxide and ammonia content were measured at the height of 1.5 m for twenty four hours in succession. At the same time outdoor air temperature and relative moisture were observed. During the investigation Data Logger, respective sensors and the PC AMR WinControl software were used.

Keywords:: waiting area, milking parlour, milking, area cleaning, air temperature, ammonia, carbon dioxide, oxygen, relative humidity, ventilation, cubicles.

A. Tsahkna.  
  Eesti Sordilehe kartulisortide kvaliteedi omadustest 165
Quality traits of potato varieties of the Estonian Official Variety List. Every kind of potato usage needs acceptable raw material or variety, which provides excellent quality of product. The main aim of potato breeding is to produce varieties suitable for some kind of utilization – selling in the market and cooking in the kitchen or fast food cafeterias, restaurants, or processing for products of food or starch. Every potato producer knows that locally bred varieties are most suitable for local growing conditions.

This paper is dealing with the description of quality traits of 36 listed varieties during 2002–2003 at the Jõgeva Plant Breeding Institute, as potato growers lack the information about how foreign and local varieties behave in local conditions. The most important quality characteristics as starch content, tuber quality traits (appearance, common scab, blackleg, flesh colour, shape, eye depth) have been tested in this study.

As the suitability of tubers for mechanical processing cannot be estimated solely on the basis of the external quality traits of tuber, peeling tests with abrasive peeler were carried out in order to estimate the darkening of tuber or the external knobblines/defects of tuber. The trials proved that peeling with abrasive peeler gives the best knowledge about enzymatic darkening and mechanical peeling. The varieties most suitable for abrasive peeling were: ‘Leyla’, ‘Ofelia’, Folva’, ‘Milva’, ‘Quarta’, ‘Agria’, ‘Anti’, ‘Van Gogh’ and ‘Vigri’.

The starch content of varities used in industries, though, is not of minor importance. Of the industrial varieties on the List, the few that met the required 15% starch content as the mean of trial years were: ‘Oleva’, ‘Saturna’ and ‘Van Gogh’. Of the table and industrial varieties only ‘Juku’, ‘Ando’, ‘Procura’, ‘Piret’ and ‘Asterix’ did.

Keywords: Official Variety List, potato variety, tuber quality traits (appearance, common scab, blackleg, flesh colour, shape, eye depth) starch content, abrasive peeling.

M. Vadi, A. Jürgenson, H. Kaldmäe, A. Olt.  
  Ristiku ja kõrreliste segude ning nende silo toitainete lõhustuvusest veiste vatsas 172
Ruminal degradability of clover-grass mixtures and silages. The objective of the study was to determine the nutritive value of fresh mixtures and silage of red clover and grass (75% and 50% red clover), and to study degradability kinetics of crude protein and neutral detergent fibre (NDF) in the rumen. It was investigated to which extent the value of effective protein degradability is affected by the washing loss of feed particles from nylon bags, by microbial contamination and passage rate.

In sacco experiments with fistulated cows were arranged. Feed samples were incubated in the rumen for 2, 4, 8, 16, 32 and 64 hours. According to the nutrients degraded in different incubation hours, the effective degradability of protein and NDF was calculated.

The experiment revealed that protein degradability was more rapid in silage than in fresh grass. In 8 hours more than 50% of the protein of the fresh clover-grass mixture was degraded. In two incubation hours 78.2% of protein of test silage 1 prepared from the same material (75% clover) and 76.8% of test silage 2 (50% clover) was degraded. The effective protein degradability of fresh clover-grass mixture 1, the test silage and silage with AIV-2000 was 64.4%, 85.2% and 79.7%, respectively. In mixture 2 these values were 68.0%, 83.8% and 78.0%, respectively.

Effective degradability of NDF in clover-grass silages ranged between 28.7 and 33.9%.

As the result of the washing loss of feed particles from nylon bags, the effective protein degradability increased by 1.6 to 1.8% in grass and by 4.1 to 4.6% in silages. In calculating effective degradability it is necessary to choose the right passage rate. At a passage rate of 8% per hour, the effective degradability of the fresh clovergrass mixture 1 was by 18% and in test silage by 15.4% lower than at a passage rate of 5% per hour.

Keywords: silage, additive, neutral detergent fibre, crude protein, degradability

V. Viljasoo, J. Treial, I. Tomson.  
  Külmavahetusosaga geotermiline seade ruumide kütmiseks ja sisekliima parendamiseks 181
Geothermal equipment with cool exchange device for heating rooms and improving of indoor climate. Geothermal equipment consists of intake air pipes, vacuum wards and underground connecting pipes, placed near to a villa. The heat exchange ventilation equipment Onninen 100 used in ventilation systems makes air inside the device circulating.

This patented equipment differs from the analogues form Germany, Japan, United States etc. by the cool exchange device. This device enables remarkable advantages in mounting and construction as decreasing the length, installation depth and number of air pipes, simplifying and cheapening the maintenance and increasing the equipment durability.

The geothermal equipment is meant for creating the environment with a constant temperature 4 ºC and adjustable relative humidity in warehouses and basements. It is for improving indoor climate in villas’ basements, preheating, and air conditioning based on air heating as well. This equipment is indispensable when preheating greenhouses and cooling air in hot season.

The analysis of air climate parameters (temperature ϑk, relative humidity Ws, dew point ϑp, absolute humidity Wa, velocity v, oxygen content O2, carbon dioxide content CO2, positive light air ions n+, negative light air ions n–, positive and negative heavy air ions N+, N–) passing through the geothermal equipment, is made in the article.

Heat technical data (air specific heat capacity, characteristics of heat and cold exchange processes) are presented.

This article summarizes the research results of indoor climate qualities and presents data about energetic-economical efficiency of the geothermal equipment (air specific heat and gross capacities, return-flow air specific heat and gross capacities, the economic effect of pre-heating the villa and the post-heating expenses were analyzed).

Keywords: geothermal, equipment, climate, environment.